Make sure we have leading directories under refs/{heads,tags}
Make sure we have leading directories under refs/{heads,tags}

Otherwise having subdirectories under refs/heads becomes rather
unwieldy.

Signed-off-by: Junio C Hamano <dc50d1021234060e53ec42a77d526afa2fe07479@cox.net>

destenson/git,destenson/git,destenson/git,destenson/git,destenson/git,destenson/git,destenson/git,destenson/git